According to Descartes' Rule of Signs, can the polynomial function have exactly 5 positive real zeros, including any repeated zeros? Choose your answer based on the rule only.f(x)=x5−8x4+8x3−4x2+7Choices:(A)yes(B)no
Q. According to Descartes' Rule of Signs, can the polynomial function have exactly 5 positive real zeros, including any repeated zeros? Choose your answer based on the rule only.f(x)=x5−8x4+8x3−4x2+7Choices:(A)yes(B)no
Apply Descartes' Rule of Signs: First, let's apply Descartes' Rule of Signs to f(x)=x5−8x4+8x3−4x2+7.
Count Sign Changes: Count the number of sign changes in the coefficients: 1 (from x5 to −8x4), 2 (from −8x4 to 8x3), 3 (from 8x3 to −4x2), and 4 (from −4x2 to x51).
Analyze Possible Real Zeros: According to Descartes' Rule of Signs, the polynomial can have at most 4 positive real zeros or fewer by an even number.
Determine Real Zeros: So, the polynomial can have 4, 2, or 0 positive real zeros.
Conclusion: Since 5 is not an option, the polynomial cannot have exactly 5 positive real zeros.